Frequency multiplier



Sept. 10, 1935. r M, OSNOS 2,013,806

FREQUENCY MULTIPLIER Filed April 2, 1932 INVENTOR ATTORNEY Patented Sept. 10, 1935 U STATS PATENT OFFME FREQUENCY MULTIPLIER Mendel Osnos, Berlin, Germany,

assignor to tion of Germany Application April 2,

1932, Serial No. 602,864

In Germany April 8, 1931 1 Claim.

This invention concerns an arrangement for frequency multiplication in a vacuum tube.

In describing my invention reference will be made to the drawing throughout which like ref- 5 erence characters indicate like parts and in which:

Fig. 1 illustrates a frequency changer of the type involved in the present invention. The frequency changer of Fig. l is known in the art.

Fig. 2 illustrates a frequency changer of the type shown in Fig. l and has as a novel feature, an additional tuned loop in the anode circuit which enhances the operation of said system.

Fig. 3 is a circuit diagram of an arrangement similar in some respects to the arrangement of Fig. 2. However, in Fig. 3 oscillations are generated in the tube rather than supplied thereto as in the arrangement of Fig. 2.

Fig. 4 is a modification of the arrangement of Fig. 2 and includes as a novel feature several additional tuned units in the output or anode circuit.

A circuit arrangement known in the prior art adapted to doubling of the frequency by means of a vacuum tube is shown in Fig. 1.

The grid g of the tube 1, by the aid of a flywheel circuit (L'l Cl) tuned to the fundamental wave k1, is fed with a potential of fundamental frequency. By suitable selection of the negative grid potential e the plate potential is distorted so that by the agency of a circuit (L2 C2) tuned to wave A2 it is possible to derive therefrom a potential of double the fundamental frequency. Anode potential is supplied by a source 3 shunted by condenser 4.

The potential of double frequency is fed by way of a coupling means K to another tube or else to some consumer device.

Now, this scheme well known in the earlier art has the disadvantage that a heavy current of the fundamental wave is caused to flow through the tube, and this current not only means an unnecessary load or ballast for the tube, but it also weakens the useful second harmonic of the plate potential.

According to the present invention (Fig. 2),

the plate circuit of the tube, in addition to the load or useful circuit (L2 C2) contains also a fly-wheel circuit (L1 Cl) tuned to the fundamental wave x1, said fiy-wheel circuit thus constituting a block (stopper) for the fundamental wave.

If it is desired to obtain from the tube directly a higher harmonic, say, the fourth overtone, it may be suitable under certain circumstances to include in the plate circuit, in addition to the fly-wheel circuit for x4 and the stopper for wave 5 Al, another stopper for wave 72 or stoppers or large inductive reactances for other harmonic waves as illustrated in Fig. 4.

The use of the invention proves particularly 1o advantageous in connection with crystal-excited tubes (Fig. 3) inasmuch as the stopper for wave x1 serves at the same time for the excitation of the crystal (Fig. 3).

I claim:

In a frequency multiplier, a thermionic repeater tube having anode cathode and control grid electrodes, a circuit including an inductance connected between the control grid electrode and cathode of said repeater tube, a circuit for impressing oscillations to be multiplied on said inductance, a condenser connected in parallel with said inductance for tuning the same to the frequency of the oscillations to be multiplied, a source of direct current in said first named circuit for applying a negative potential to the control grid electrode of said repeater tube, an output circuit connected between the anode and cathode electrodes of said tube, said output circuit including a source of potential for applying a positive potential to said anode whereby oscillations of complex form including said fundamental frequency and harmonics thereof are produced in said output circuit, a plurality of inductances in series in said output circuit, a tuning capacity in parallel with each of said inductances, certain of said capacities tuning certain of the inductances each to a different harmonic of the frequency of the oscillations impressed on said inductance connected between the control electrode and cathode of said tube, one of said capacities tuning the inductance in parallel therewith to the said fundamental frequency whereby said fundamental frequency and certain of said harmonic frequencies are prevented to a certain extent from flowing through said output circuit, and a work circuit coupled to one of said inductances in said output circuit which is tuned to a harmonic of said fundamental frequency.

MENDEL OSNOS. 

